Observation of new excitation channel of cerium ion through highly vacuum ultraviolet transparent LiCAF host crystal

The transmission spectra of LiCaAIF(6) (LiCAF) and LiSrAlF6 (LiSAF) are inv estigated in the ultraviolet (W) and the vacuum ultraviolet (VUV) region. T he transmission edge of LiCAF (112 nm) shows almost the same value as that of LiF. Taking into account difficulties of material processing and polishi ng due to the cleavage or the hydroscopic nature of LiF, LiCAF is regarded as a more suitable optical material in the UV and the VUV region. Moreover, the new excitation channel around 112 nm is discovered for Ce:LiCAF crysta l. This excitation is originated not from absorption of Cerium ions but fro m absorption around the bandgap of the host crystal. (C) 2001 Elsevier Scie nce B.V. All rights reserved.